import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet("/login")
public class LoginServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf8");
        String name = req.getParameter("username");
        String password = req.getParameter("password");
        if(name == null || password == null || name.equals("") || password.equals("")) {
            resp.setContentType("text/html; charset=utf8");
            resp.getWriter().write("输入的名字或密码不能为空");
            return;
        }
        if (!name.equals("zhangsan") && !name.equals("lisi")) {
            // 用户名有问题
            resp.setContentType("text/html; charset=utf8");
            resp.getWriter().write("用户名或密码有误");
            return;
        }
        if (!password.equals("123")) {
            // 密码有问题
            resp.setContentType("text/html; charset=utf8");
            resp.getWriter().write("用户名或密码有误");
            return;
        }
        HttpSession session = req.getSession(true);
        session.setAttribute("username",name);
        resp.sendRedirect("index");
    }
}
